The invention relates to a vessel with a locking lid recessed in its wall, and a mechanism for moving the lid. The vessel comprises a mobile supporting member with a connecting element for the lid. Vessels with lids are known in various versions. Larger lids, however, sometimes require a complicated and moreover, extensive mechanism which may be disadvantageous.
These complications in the known vessels occur because the lid is recessed in the wall of the vessel, so that a pivot cannot possibly be utilized. In order to ensure a liquidproof or gastight sealing along the edge of the lid sometimes additional means are required.
This invention provides a mechanism for moving the locking lid. The mechanism is constructed from rather simple parts and yet ensures an efficient locking and opening. The connecting element between the supporting member and the lid consists of some rods, which are pivotally connected both with the lid and with the supporting member. When the lid is locked the pivotal points of the rods substantially coincide with the angular points of a rectangle. In such a mechanism the supporting member need only be moved along the wall of the vessel and at a slight distance therefrom whereby the lid will then move in a transverse direction relative to the wall of the vessel. In the locked position a toggle joint effect will be produced in the rods, whereby the lid can be strenuously pressed in place.
The mechanism can be constructed in various ways. A correct transverse movement of the lid can be obtained in a construction in which the rods are mutually parallel and have an identical length, while the supporting member is movable in a direction forming an angle, ranging from 0.degree. to 30.degree., with the wall of the vessel. Thus a kind of parallelogram structure is obtained whereby the lid is lifted without any tilting or turning movement, or pressed down again.
Sometimes it is desirable to displace the lid not only in a transverse direction but subsequently also in a direction longitudinal to the wall of the vessel. This is particularly of importance when the lid is accommodated in the lower wall or bottom of a vessel. Under these circumstances the lid may form a barrier for the material flowing from the cleared opening. The present invention provides also a solution to the situation that occurs when the pivotal points between the rods and the lid only allow a limited angular displacement so that after reaching the maximum deflection resulting from displacement of the supporting member, a further movement of this member results in a movement of the lid in a direction parallel to the wall.
The transverse movement of the lid can be limited to a distance corresponding to the wall thickness of the vessel, whereupon the lid moves laterally along the wall. In case of a circular lid, a crescent shaped outlet is first formed, which finally becomes a completely circular hole. Thus this construction may accomplish a metering effect since it is a simple expedient to adjust the width of the outlet to accomplish a predetermined flow rate. The side of the lid turned to the interior of the vessel is scraped clean during the movement along the wall, which may be of importance in the case of a product tending to stick thereto.
The supporting member can be driven by motor but also manually, the latter manner being simpler and less expensive.